Empirical Validation Using MAI Motion
The 3-Repetition
Sit-to-Stand Protocol.
A clinical validation study demonstrating that three repetitions provide biomechanical data equivalent to the conventional five — reducing participant burden and fatigue without compromising scientific rigour.
20
Adult Participants
5 → 3
Repetitions
RGB
Markerless Capture
Why This Study Was Needed
A simple but important clinical question.
The sit-to-stand test is one of the most widely used functional assessments — but many real-world patients (arthritis, post-operative pain, frailty, fatigue) struggle to complete five repetitions.
Can we obtain reliable biomechanical data with fewer repetitions, without compromising quality?
Provides insight into
Headline Finding
Three repetitions are enough.
5-Rep Protocol
Conventional Standard
100% of repetitions · greater fatigue burden
3-Rep Protocol
Equivalent Output
60% of repetitions · comparable mean values · matched variability
Finding 01
No meaningful differences
Mean biomechanical values across knee, hip, ankle, core and left/right movement.
Finding 02
Comparable variability
3-rep protocol matches 5-rep variability — and in some cases shows lower variability.
Finding 03
Reliable across age
Three repetitions remained as reliable as five across the age ranges studied.
Why It Matters Clinically
Less fatigue.
More accessibility.
Confirming three repetitions are sufficient changes who can be assessed, where, and how often — particularly valuable for older, frailer, and post-operative patients who could not reliably complete five.
Key Insight
A 40% reduction in test repetitions, with no measurable loss in biomechanical signal — keeping protocol rigour while making it reachable.
Faster
Assessments
Less chair time per participant frees clinical throughput across the day.
Reduced
Patient Burden
Lower physical effort and fatigue — fewer mid-test drop-offs in fragile cohorts.
Greater
Compliance
Older and post-operative patients are more likely to complete the protocol.
Broader
Inclusion
Functional testing opens to populations that five-rep protocols quietly excluded.
Clinical Application Areas
Evidence drives evolution.
These findings inform protocol optimisation, remote assessment workflows, and AI model refinement inside MAI Motion. Published science — not assumption.